Deaths highlight avalanche risks in Sierra -- Surviving an avalanche

The recent spate of avalanches at Sierra ski resorts, some of them deadly, offers a reminder of potential peril when heavy snow layers the slopes under certain conditions, experts said Wednesday.

As always, the biggest danger of snowslides lies in the backcountry. But recent events show there’s risk even at places carefully monitored by trained personnel paid to ensure safety of skiers and snowboarders now massing at ski resorts for the holidays.

After two skiers escaped serious injury during a Sunday avalanche that a witness said was triggered by snowboarders at Squaw Valley, two more slides occurred at Sierra resorts on Monday. One buried and killed a snowboarder at Donner Ski Ranch, and the second claimed the life of a veteran ski patroller at Alpine Meadows.

The slides occurred after storms dropped up to 5 feet of snow over the weekend, with a Christmas storm adding more than a foot. In the backcountry, recent snows settled atop an older snowpack that is weak and prone to fracturing into slides, experts said.

“It’s a very real danger, and it will take some time to settle down,” said Denny Hogan, winter sports specialist with the U.S. Forest Service’s Truckee Ranger District, which monitors the backcountry for avalanche danger.

On Wednesday, the Sierra Avalanche Center rated the danger of backcountry slides as considerable both above and below the treeline on slopes facing north, northwest, northeast, east and southeast with a steepness of 32 degrees or more.

All other slopes had a moderate risk, with “large, destructive, human-triggered avalanches likely” and natural slides also possible, the center said.

“Dangerous avalanche conditions exist,” the center’s statement said.

With fresh, wet snow sitting atop the weak snowpack left from wet, warm storms earlier this month, the risk is considerable, Hogan said.

“That existing snowpack is failing, and you’re seeing more natural avalanches and people triggering avalanches,” Hogan said. “You can have large avalanches, and that’s what we’re seeing now.”

Backcountry safety

Check for avalanche warnings at the Sierra Avalanche Center and get latest weather forecasts. On the Web:www.sierraavalanchecenter.orgOptions available to gauge snowpack stability include digging snow pits and doing shear tests. Keep an eye out for cracks shooting across the surface, or small slabs shearing off. Listen for hollow or “whumping” noises as you walk or ski. Avalanche safety gear: Proper equipment is a critical factor in rescue efforts. Avalanches kill either with fatal trauma — collisions with rocks or trees — or victims suffocate after they are buried by snow. Gear includes portable shovels made of plastic and aluminum; collapsible probes or ski-pole probes, usually consisting of 2-foot tubes of steel that join together to make a probe 10 to 12 feet long; and avalanche beacons, transceivers that emit a frequency that other transceivers can home in on. The buried skiers must have their units set to “send.” Source: Reno Gazette-Journal research

Surviving an avalanche

If you are caught in an avalanche: • Travel off the slab at a 45-degree angle before it breaks up and tumbles you. • If the slide knocks you over, keep your feet downhill and try to dig into the bed surface and let as much debris as possible pass you. • Use swimming motions and fight hard. As the slide begins to slow: • Clear an air space in front of your face. • Thrust a hand toward the snow surface. • Try to remain calm. Source: U.S Forest Service National Avalanche Center